This invention relates to an unmanned, magnetically guided vehicle which carries various loads in a fully automated fashion, in a factory or a warehouse, along a guide path of a closed-looped magnetic tape.
Various kinds of automatically guided vehicles (AGV) which carry various loads along preset guide paths in factories, warehouses and golf courses have been developed and put into practice both domestically and abroad. In the Japan's Patent Publication No. S62-268511, for example, a motion controller for a magnetically guided vehicle which is equipped with a sensor to detect a magnetic guide band for steering control is disclosed. In the Japan's Patent Publication No. S62-288908 a guide system for a magnetically guided vehicle which uses magnetic guide band is disclosed. In the Japan's Patent Publication No. S62-288910 a motion control device for AGVs in a system which includes paths on which AGVs have priority paths and non-priority paths which join the priority paths is disclosed. In the Japan's Patent Publication No. S68-91708 a guide system for AGVs wherein a sensor-active area which is recognized by a sensor for steering control for each of the AGVs is provided, and each AGV contains a guide device which controls steering by keeping the boundary between said sensor-active area and the non-active area as close as possible to a predetermined position using the information from the sensor is disclosed. Further, in the Japan's Patent Publications No. S62-199811 and No. S63-126907 bands for magnetic guidance are disclosed.
As seen from the above, both technical development and practical use of AGVs seem to have reached a high level of sophistication. But, possible areas of application, equipment costs and installation, etc. are fields in which there is still room for study. A vehicle which is constructed as a proper AGV, for example, develops a lot of resistance (especially magnetic resistance of the motor) when it is pushed to a place off the magnetic guide path in order to change paths or to moved the AGV to a charging station in order to charge the battery, making it very difficult to push it by hand.
The primary object of the invention is, therefore, to provide a magnetically guided vehicle system with excellent versatility and variability using guide paths consisting of magnetic tape laid along the path lines and a magnetic-guided steering drive unit which has a magnetic sensor to detect magnetism from the tape. The vehicle system also has a drive wheel, a driving means to drive the drive wheel and a steering means for the wheels, each provided under an attachment plate, a trolley to which the attachment plate for the steering drive unit is attached on the lower surface of the chassis, and a carriage shelf assembly provided with one or more layers of automatic conveyers mounted on the chassis of trolley. The magnetically guided vehicle would be able to be used either as a magnetically guided vehicle system when the trolley, steering drive unit and carriage shelves are combined, or as an normal trolley when disassembled.
Another object of the invention is to provide a magnetically guided vehicle which has the drive wheel of the steering drive unit touching the floor with a pressure sufficient for running and can be changed so that the drive wheel is suspended above the floor, making it very convenient for hand pushing when the vehicle must be moved to a place without magnetic guide tape in order to change paths or to a charge station, having no guide path, for charging batteries.